Poor sleep quality in early middle age may be linked to signs of faster brain aging in later life, according to a new study.

Published in Neurology, the medical journal of the American Academy of Neurology, the research suggests that people in their 40s who have trouble sleeping or staying asleep for longer periods of time are less likely to experience brain aging by their late 50s. More symptoms appear.

While the study doesn’t prove that poor sleep speeds up brain aging, it does show a strong link between poor sleep and a greater decline in brain health.

“Previous research has linked sleep problems to poorer memory and thinking skills later in life, leading to an increased risk of dementia,” said the study’s lead author, Dr. Clemens Cavallis of the University of California, San Francisco. “Our findings show that poor sleep in middle age is associated with approximately three additional years of brain aging.”

The study initially followed 589 people with an average age of 40 years. The participants completed sleep questionnaires twice, once at the beginning and again after five years, and they had brain scans 15 years after the study began.

The scans helped researchers estimate the age of each participant’s brain based on signs of brain shrinkage, a known marker of aging.

The participants were grouped based on their sleeping habits. The low-risk group had one or no sleep problems, the middle group had two or three, and the high-risk group had more than three. At the beginning, 70% of the participants were in the low-risk group, 22% in the middle, and 8% in the high-risk group.

The results showed that the average brain age of people in the middle group was 1.6 years older than that of people in the low group, while the average brain age of people in the high group was 2.6 years older.

Specific sleep problems, including poor sleep quality, difficulty falling asleep, and waking up too early, were associated with faster brain aging, especially when experienced consistently over time.

Dr. Christine Yaffe, co-author of the study, said, “Addressing sleep problems early can help protect brain health. Maintaining a regular sleep schedule, exercising, and using relaxation techniques can improve sleep. There are some ways to improve.”

They stressed the need for future research to explore ways to improve sleep quality in young people and its long-term effects on brain health.

Although the findings are promising, the study had one limitation: participants self-reported their sleep problems, which could lead to inaccuracies.